Ayumi Kuramoto

Ayumi Kuramoto (倉本 歩, Kuramoto Ayumi) is a student at Kaimei High School. Though she and Yagi are very competitive when it comes to their grades, they are actually good friends. She asks the Sket Dan for help in cheering Yagi up when the latter seems in dire straits.

Manga Debut: Chapter 15 (You Mustn't Watch It)
Anime Debut: Episode 10 (You Mustn't Watch It)

(source: sketdance.wikia.com)